How many degrees are in the measure of the smaller angle that is formed by the hour-hand and minute-hand of a clock when it is 5 o'clock?
Explanation: [asy]
unitsize(0.8inch);
for (int i=0 ; i<=11 ;++i)
{
draw((rotate(i*30)*(0.8,0)) -- (rotate(i*30)*(1,0)));
label(format("%d",i+1),(rotate(60 - i*30)*(0.68,0)));
}
draw(Circle((0,0),1),linewidth(1.1));
draw((0,0.7)--(0,0)--(rotate(-60)*(0.5,0)),linewidth(1.2));
[/asy]

There are 12 hours on a clock, so each hour mark is $360^\circ/12 = 30^\circ$ from its neighbors.  At 5:00, the minute hand points at the 12, while the hour hand points at hour 5.  So, the angle between the hands is $5\cdot 30^\circ = \boxed{150^\circ}$.